A chain tensioner includes an oil supply passage for supplying hydraulic oil into a pressure chamber defined by a cylinder and a plunger, and a check valve provided at the end of the oil supply passage. A leak gap is defined between the sliding surfaces of the cylinder and the plunger. The plunger is biased by a return spring in the direction in which the plunger protrudes out of the cylinder. A plug is press-fitted in a cylindrical inner periphery of a through hole formed in the plunger to extend from a protruding end surface of the plunger to the pressure chamber to define an air vent passage. It is possible to change the hydraulic damper force simply by replacing the plug with another different kind of plug to define a different air vent passage.

A chain tensioner is provided which is configured such that the air remaining in a pressure chamber can be discharged to the outside through a helical gap defined between a screw and a threaded hole, and through between circumferentially separate radial ends of a spring washer mounted between the screw and a housing. The chain tensioner includes an air discharge groove or grooves formed in the seat surface of the head of the screw such that an annular space defined between the neck of the screw and the inner diameter surface of the spring washer communicates with the outside through the air discharge groove or grooves. Even if foreign objects clog the space between the separate radial ends so as to hinder air from being discharged through between the separate radial ends, the air remaining in the pressure chamber can be discharged to the outside through the air discharge groove or grooves.

A belt drive system includes a housing, a first pulley and a second pulley rotatably disposed in the housing, a belt that connects the first pulley with the second pulley, where the first pulley drives the second pulley via the belt. The belt drive system includes a cover rotatably coupled to the housing with a rotating mechanism, such that the cover is moved between a closed position and an open position with respect to the housing. The belt drive system also includes safety device having an actuating element mounted on the cover and a projection unit mounted within the housing to provide a first caution based on a proximity of the actuating element with respect to the projection unit, where the first caution is indicative of a movement of the cover from the closed position.

A mounting alignment apparatus may include a rail assembly including a first pair of alignment surfaces. The mounting alignment apparatus may also include a slide assembly including a second pair of alignment surfaces. The first and second pairs of alignment surfaces may define an interacting capturing geometry therebetween, permitting sliding movement of the slide assembly relative to the rail assembly along a first axis, and restricting movement of the slide assembly relative to the rail assembly about an axis other than the first axis. The mounting alignment apparatus may also include a tension adjustment assembly coupled between the rail assembly and the slide assembly for positioning the slide assembly relative to the rail assembly along the first axis.

A number of variations may include a product including a tensioner for a vehicle engine chain comprising a piston housing body portion having a piston bore formed therein for slideably receiving a piston connected to a chain guide shoe, and a camshaft bearing support or a combustion engine cylinder block or an engine cylinder head, extending from the body portion.

The problem to be solved by the present invention lies in making it possible to reduce costs and to reduce the size of an oil pump, without impeding the degree of freedom in chain layout. An oil jet 1 is constructed in order to supply lubricating oil to a tension-side span of a chain C while also causing a tensioning force to act on a slack-side span of the chain C. The oil jet arm 1 is provided with a pivoting-side part 2A, and a tip-end side part 2B which is provided in such a way as to be pivotable about the pivoting-side part 2A and is acted on by a pressing force from a piston 41 of a hydraulic tensioner 4, and an oil ejection hole 22a for ejecting to the outside oil supplied from an oil discharge hole 41a in the piston 41 is formed in the tip-end side part 2B. Oil ejected from the oil ejection hole 22a is supplied to a portion E on the meshing start side with a sprocket 100 on the tension-side span of the chain C.

A tensioner system for a flexible drive member has: a slider configured for abutting the flexible drive member; a tensioner body supporting the slider; a biasing member arranged for biasing the slider toward the flexible drive member via the tensioner body; and a latch having a latched position and an unlatched position. In the unlatched position, the latch permits the biasing member to move the slider toward the flexible member. In the latched position, the latch prevents the biasing member from moving the slider toward the flexible member. A drivetrain and a vehicle having the tensioner system are also disclosed.

Some embodiments provide a belt tensioning mechanism for a 3D printer and a 3D printer. In those embodiments, the belt tensioning mechanism comprises a base, a driving pulley, at least one timing pulley, a sliding block, a tensioning pulley, a spring. The base is provided with a first sliding groove. The driving pulley and the at least one timing pulley are mounted on the base and are connected in series with each other via a belt. The sliding block is mounted on the base and is capable of sliding along the first sliding groove. The tensioning pulley is mounted on the sliding block and is connected in series with the driving pulley and the at least one timing pulley via the belt so as to tension the belt. The spring is configured to apply an elastic force to the sliding block.

A drive mechanism includes a mount block extending along an axis and a plurality of electric motors supported by the mount block. The electric motors are arranged in series along the axis to define an initial electric motor, one or more intermediate electric motors, and a final electric motor. The drive mechanism also includes a gear mounted to each of the electric motors, and an output member driven by the gear mounted to the final electric motor to receive the combined rotational torque from the gears of the series of electric motors.

A toothed CVT using a Cone with One Torque Transmitting Member that is coupled by a Transmission Belt to another Cone with One Torque Transmitting Member for which teeth re-engagement between the Torque Transmitting Members and their Transmission Belt is improved. Said CVT uses a slack-side Tensioning Pulley in order to maintain the tension in the slack-side of the Transmission Belt almost constant so as to ensure smooth re-engagement of the Driven Cone; and a Transmission Diameter Compensating Mechanism, which increases the Transmission Diameter of the Driving Cone when the torque being pulled by the Driving Cone is increased, in order to compensate for an increase in Transmission Belt Teeth Compression and an increase in stretching of the tense-side of the Transmission Belt, due to an increase in tension in the tense-side of the Transmission Belt when an increased torque is transmitted; to ensure smooth re-engagement of the Driving Cone.